Underfeed furnace



s. A. ARMSTRONG AND A, H.. BLA0KBURN.

uunERFEEnTunNAbE. AIPLICATION. FILED IUIIE 9. 1919. l g 1,333,696- Patented Mar.16;192 0.

Tm" y m Mp3s,

AAAM A Is. A.'ARN|ST RONG ANDA. H. BLACKBURN.

` uNnERFEEp 'FuRNAcL' ,JMPLICATION FILED JUNE 9, 1919.

A Patented Mar.l1-6,v192o.

UNITED STATES PATENT OFFICE- SAMUEL-A. ARMSTRONG, OF TORONTO, ONTARIO, CANADA, .AND ARTHUR H. BLACK- I BURN, 0F DOWNERS GROVE, ILLINOIS, ASSIGNORS TO UNDER-FEED STOKER COM- PANY 0F AMERICA, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

UNDERFEED FURNACE.

specification of Letters rtent. luttent-edv Mar. 16, 1920.

Application fuea June 9,1919. serial No. 302,822.

To all whom t may concern.'

Be it known that we, SAMUELA. ARM- sTRoNc and ARTHUR H. BLACKBURN, subjects of the King of Great Britain', residing at Toronto, Ontario Province, Canada, and.

Downers Grove, in the county of Dupage and State of Illinois, U. S.`A., respectively, have invented certain new anduseful 1m'- proveniente in Underfeed' Furnaces, of

which the following is a specification. y

Our invention relates to .underfeed furnaces and, in' some respects, partcula sidedump, singleretort constructi which the .fuel is fed rearwardly the furnace from a single supplydistributed laterally across the ir Som'e ofthe objectsof our .inventioii--are to increase materially the hitherto-attainable capacity of such furnaces making them available for boilers which hitherto would have .required other and more expensiveI types of Stoker-construction; to :insure most n effective and completel ycombustion of the fuel.; to secure desirably uniform,'re'gulated distribution of the fuel; and to attain many advantages-of simplicity, 'ruggedness and construction and ease of y ings showing a single embodiment of our invention for purposes of disclosure In the drawings, y Figure 1 is a plan view of the rebox floor with parts broken away; t

Fig. 2 is a longitudinal section; Fig. 3 is a transverse section;

thereof.

Fig. 4 is afragmentary front elevation; i' i Fig. 5 is a twyer-lock detail.

The fuel is fed from an outside hopper 10= by a ram 11 through a throat 12 into a. re-4 tort 13 which forms part of the fire box floor that extends from the front-wall 14' to the transverse bridge wall 15. The rain,

as shown, comprises a cylinder 16 opening endwise to the somewhat-Haring throat .12,

and having a top orifice to the hopperin the zone of reciprocation of a piston or-plunger 17 which is reciprocated atproper intervals by a suitable-"powerdeviceV such' as steamengine 118.v The plunger has an arm 19 depending througha cylinder-slot 2Q and carrying, cross-pin 21 :to coact lwithl afpusher,v or feed element, to-be described. Thus-far,

only matters ofcommon practicefhavefbeen stated.

l The ere-bea naar' falacias. the affita-,aon

chamber k22 aboveflfrom"'thefcentral wind below, the wind box 23, to airl under pressure is supplied by usual` means (not ash pits by longitudinal partitions 25..'v Y These are preferably rvertical frame membersfresting on the foundation and cross-connected by beams 26 on whichjthe retort centrally bea-rs through a foot-rib 27.l VOn this framework mostof thepartsof theffire-box floorwork are supported.

The -retort 13 has a main-.channel or fueltrunk 30, preferably of flaring-sided, roundbottomed-trough shape in cross-section with its bottom up-sloping 'somewhat from front to rear and its rear end'upsloped steeply-and provided'witha rentrant prow, or upwardly-inclined, sidewise-flaring deiector 31, the

upper edge of the main-retort casting preferably being substantially horizontal from front to rear.l From this main retort-trunk v run lateral, or branch retorts 32-a suitable number of them (say four) on each side,

preferably disposed in transversely-aiming pairs on opposite sides of the trunk, and all preferably at substantially right angles to the lmain channel. These branch retorts, as shown in Fig. 3, preferably have up-sloping bottoms, each bottom having an off set portion 33 or out-facing shoulder, 'and the branches have down-sloping top-edges; .the

top and bottom slopes converging tounion near the longitudinal plane of the partition 25.- In cross-section (Fig. 2*) the branch-retorts preferably flare upwardly from rounded bottoms, and their bottoms may merge into the bottom curves of the main-trunk as shown in Fig. 3. The branch retorts are preferably quite close together-making the side-wall posts 34.0f the main retort narrower than the branch-retort mouths, and

4 l' shown) being separatedvfror'n. the'fl'anking' and is laterally delivered,l as ash,j to.. 1dumps.V lparalleling the furnace-sides;`

Marginally around all of the branch-retorts and the main-retort side-posts twyers are provided, to deliver air from the windboX below into the fuel, so that as green fuel is fed rearwardly along'the trunk or main channel, and laterally through the several branch channels, it receives its air supply substantially throughout its entire progress in the fashion which is best characteristic of Kunderfeed practice, namely above the lowest green fuel'stratum and below the actively burning or partly consumed fuel. This -is of great advantage in many particulars, since the fuel along the zones adjacent the side dumps is not burned out until it is` at the eXtreme margin of the combustion space, but comes across properly coked, re-

: ceiving its" air in ample quantity and in most effective manner, with the progressivelythinning under-stratum of fuel in the outer ends of the lateral branches fully fired and consumed before it reaches thev ash dump doors, and with a resultant intense-broadspread fire throughout the whole effective floor-space, which enables a furnace thus constructed to serve a boiler of much greater capacitythan does any part-uiiderfed and part-overfed (or grate) construction of the same floor-dimensions o f which we are aware.

It is important, in a construction as above described, that the fuel-feed-.through the relatively long main-trunk and long lateralbranches should be properly regulated and out and also it is desirable that this feed'A should exert a strong clinker-breaking effeet in the main and branch retorts. To

these ends feeding devices supplemental to the ram are provided. The main retort has therein a pusher rod 40, guided ,at 41, extending out below the throat and connected for variable-lost-motion to the plunger-arm 19 by two piv'oted link-ineinbers 42, straddling the arm 19, resting on the pin 21, united by a rear bolt 43, and carrying an adjustable stop-pin 44 to receive which aI series of holes are made in the links. On this rod the pusher'heads 46 and 47 are adjustably secured by set screws 48, these heads being retort-bottom-itting blocks with ab-rupt, nearly-vertical rear faces and steeply-inclined front-top surfaces, whereby they tend to push the fuel rearwardly on the in-strokeof the ram, and to lift the fuel with clinker-breaking effect and side-feed portant.

ing tendency on the outstroke of said rain.

By adjusting the pusher-heads along the rod l the effective distribution of fuel may be modified and regulated to insure proper supply' to all of the branch-retorts. Additional feeding devices are provided in the branch retorts, a. pusher bar slidably eX- teiidiiig through the shoulder 33 of each branch-retort bottom, each such pusher having a head 51 and below the iiiboard portion of the retort bottom, having a .rack 52. Each such rack coacts with a gear-sector 53 arranged on a shaft 54 f-or oscillation to reciprocate the pusher.

VAs an effective, preferred means for rocking the shafts so as variavbly to regulate the feedingaction of these auxiliary pushers, the roc'kshafts 54, nextended. beyond the front wall, have levers 55 straddling a bar 56 reciprocable in harmony with the ram actionas by a steam engine 57, said bar carrying adjustable stop blocks 5S for giving any desired lost motion in the operation of the rock shafts, so as to give different lengths of stroke to the pushers 50. These in'g the furnace of clogging or undue fuel- Apacking and they carry the fuel positively along the branch-lines beyond the distance that the coal could be made to progress by the feeding action of the ram andr main pushers.

In the construction of a ietortvsysteni as described the trunk-retort 30 may be a casting with branch-retort lstubs 60 integral therewith, flanged as at 61 to receive the flanged root-ends 62 ofthe branch retorts, each of Which is a casting having at its leaving-end or outer extremity a flange 63 supported from the frame-member 25 through an interposed Z-beam 64, these parts being apertured as at 65 to receive twyer-tonguesn hereafter to be described. When these several parts are bolted together the Firebox` floor, of especially solid andv durable construction, iscomplete except for the twyer blocks.

Since the twyer blocks should be readily replacable and'yet must stand the strains of the combined longitudinal and lateral distribution of thecoal-mass, their mounting for strength and 'ease of placement isim- Each sidepost 34 of the main retort has an apertured top-flange 66 and a lug or iiange portion 67 preferably integral with the stub-fiange that receives the bolted-on branch retort. This lug is apertured to give bearing to a trunnion 68 of a twyer lock having a lock bar4 69 extending along' the space between adjacent branchi'etortsand having at its other end a trimiiion 70 mounted in a bearing-block 71 on the 4Z-beain 64. A lever 72 at the other end of the lock enables its bar to be swung from the locking position shown inlo branch retort sides.

Fig. 5 to an unlocking position. The several levers 72 along each side are connected by an operating rod 7 3 --Which extends through the furnace-front kfor exterior manipula-f retorts, each having an apertured cross-Walll 79 having a locking --hook 7 7.l The end tWyer blocks 80 may be T-shaped in plan, as shown, with locking hooks on their short stems, and with lugs 81 on their undersides v to pass through the openings '.65 in the retort-flanges, these lugs 81 .being apertured to receive a key-rod 82 locking all the alining lugs in place, and .extending through the furnace vfront for-easy removal from the outside.

Thusall of the twyer blocks mentioned u are removably positioned butvery strongly held; their release requiring only the withdrawal .of rods 81 and the pulling outwardly of lock-operating rods 78 to swing all lockbars 69 to. unlocking position. The twyer y blocks 83 along the front Wall and bridge- Wall are held in the fashion dcribed, but to prevent clinker-adhesion along the fire-box Walls they are preferably made high, steeply sloped, and with baffled air passages to comlpel, the air to sweep under their exposed surfaces, as best shown at 83 in Fig. 2.

Ash 'removal 'may be variously accomplished, but the simple dump-doors 85, substantially covering the ash pits and reaching practically to side Walls 86, and mounted on frame-carried rock shafts 87, exteriorly 4operatable by levers 8 8 to dump the ash. provide one simple and effective means forthis purpose, any suitable ash-'removal construction paralleling'and close to the side Walls being suflicient. A y

It Will be understoodthat while we have A described in detail a specific embodiment of our invention for full disclosure, and some details of which we may'claim for their particular advantages, We do not desire to be understood as so li-miting our inventionin itsbroader aspects, as many changes in construction and arrangement vmay be made Within the spirit of our invention andthe scope ofthe appended lclaims.

We claim:

. 1.In' an underfeed furnace, the combination of fire-box Walls, ash removal means' paralleling the side-Walls, and a fire-box- .loor'composed of a central retort and lateral-branch retorts, the latter opening to the main retort at theininner ends and extending. substantially to the lash-reni'oval means at their outer ends, said main and branch retort-s having marginal twyers alongftheir sides and across their ends, adJacent the i .floor-level.

2. In an underfeed furnace, the combinaparalleling the side-Walls, and a fire-box door composed of a central retort and lateral-branch retorts, the latter opening to thel ,tion of fire-box Walls, ash removal means main retort at their inner ends and extendfrom approximatelythe main-retort. depth atitheir inner endsto the tWyer-level at their outer ends.. l l

3. In an underfeed furnace, the combination of fire-box Walls, ash removal means `4along the side-Walls, and a {ire-box. ioor composed ofa main retortand lateral branch retorts opening thereto extending substantially to the ash removal. means, the tops of saidretorts provided with inwardly directed tWyers adapted to receive air from below the floor, and arranged on 'substantially a longitudinal level .but laterally downsloping from the main retort, the bottom of said main retort being rigid and upsloping from `front to rear and the bottoms of the branch retorts unslopingy from the main `retort bottom at their inner-ends to Athe twyer-levels at theirouter ends. i

4. In an un'derfeedy furnace the combination of a fire-box Hoor comprising a main longitudinal retort and lateral branch' retorts, the latter opening'into the former. fuel feedingnieans 'associated' with said main retort and auxiliary fuel feeding means associated vwith lthe several branch retorts.

5. In an nnderfeed furnace the combination of a' fire-box floor comprising a main longitudinal retortv and lateral branch retorts, the latter opening into the former, longitudinally reciprocable fuel feeding means `arranged to feed fuel longitudinally Vof the main retort, and laterally reciproyy cable/auxiliary feeding means in the severall branch retorts.

6. In any un'de'rfeed'furnace, a fire-boat" floor-comprising a 'main longitudinal retortw and lateral branch retorts, the latter opening at their inner ends-to the former; a fe d ram for the main. retort; and lateral iy reciprocable pushers inthe branch retorts.

feed ram for the main retort, pusher means in the main retort, and laterally reciprocable pushers in the branch retorts.

8. In an underfeed furnace, a fire-box fioor comprising a main, longitudinal retort and lateral branch-retorts, each said retort portion having a rounded, closed, upsloping bottom, and said branch retort bottoms provided with an offsetv portion; a feed ram for the main retort, feedpushers for the branch retorts, each extending through the shoulder of the offset portion, and pusher operatingy means associated with the -portions of )said pushers outside of the branch-retorts.

9. In an underfeed furnace, a main retort, branch retorts ,leading therefrom, means for feeding fuel longitudinally of the main retort, pushers in the branch rctortsand means for operating said pushers for variable throw.

10. A fire-box floor comprising a main retort and branch retorts opening thereto, detachable twyer blocks valong the margins of the main and branch retorts., and common retaining means for the twyer blocks that are along a side-margin of a retort-branch. 11. In an underfeed furnace, a fire-box oor comprising a main retort casting having side-posts, branch retort castings opening to thelnain retort between said side-posts and having side-margins and sets of detachable twyer blocks spanning the space between and resting on the margins of, adjacent branch-retorts.

12. In an underfeed furnace, a fire-box .floor comprising a main retort casting having side-posts, branch retort castings opening to thel main retort between said sideposts and sets of twyer blocks spanning the space between and resting on the margins Y of, adjacent branch-retorts, said twyer blocks having depending locking lugs and movable means coperating therewith to lock all twyer blocks of one such set.

13. In an underfeed furnace, twyer blocks having locking hooks, and a swinging lock bar for engaging and vdisengaging said hooks, respectively to lock and 'release the .twyer blocks. ,y

14. In an underfeed furnace, the furnacewalls, a lire-box oor having a main retort and lateral branch retorts opening there-v from, twyer blocks along the edges of said retorts, locking means for simultaneously engaging or disengaging a plurality of said twyer-blocks and operating means for the locking means operable exteriorly to the furnace walls.

15. In an underfeed furnace, the combination of .the fire-box walls, a main retort, lateral branch retorts paralleling the front and rear walls, and twyer blocks along the margins of said retorts, the twyer blocks adjacent the front and rear Walls upsloping steeply to said walls, and contacting therewith to present cool non-elinkering surfaces at the ends of the fuel-beds. 16. In an Iunderfeed furnace, a main retort and lateral branch retorts opening thereto, said main retort having its rear end formed into a rentrant pronT having steeply up-sloped and laterally flaring fueldeflecting side-surfaces that, at their outer a supporting frame vcarrying lsaid main retorts, said frame including side-.walls 25 carrying the branch-retort ends and cross connections 26 carryingthe main retort.

19. In an underfee'd furnace, a main Aretort having side. posts, lateral branch retorts opening between said posts and having their side walls spaced apart; twyer blocks mounted along said spaced sidewalls, other twyer blocks mounted across Athe ends of said branch retorts, and respective retaining means for the groups of sidetwyer-blocks and end-twyer-blocks all eX- tending to and releasable from the front of v the furnace.

SAMUEL A. ARMSTRONG.4 KARTHUR H. BLACKBURN.

tort and the outer'ends ofsaidbranch re- 

